Truncation of the COOH-terminal region of the paramyxovirus SV5 fusion protein leads to hemifusion but not complete fusion
Truncation of the COOH-terminal region of the paramyxovirus SV5 fusion protein leads to hemifusion but not complete fusion
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DOI：
10.1083/jcb.135.1.73
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发表时间：
1996-10-01
影响因子：
7.8
通讯作者：
Lamb, RA
中科院分区：
文献类型：
--
作者：
Bagai, S;Lamb, RA
通过构建一系列COOH-末端截短突变体，研究了猴病毒5（SV 5）融合（F）蛋白20个残基的COOH-末端区域（被认为代表胞质尾区）在融合活性中的作用。当使用牛痘病毒-T7瞬时表达系统在真核细胞中表达改变的F蛋白时，所有F蛋白都表现出相似的细胞内转运特性，并且都在细胞表面大量表达。定量和定性的细胞融合试验表明，所有的F蛋白羧基端截短突变体介导的脂质混合与野生型F蛋白的类似的动力学和效率。然而，细胞质内容物混合活性下降的F蛋白COOH-末端截短突变体中的删除的程度平行。这些数据表明，它是可能的，以分开的融合反应，半融合，融合的最后阶段，内容物混合的推定的早期步骤，和F蛋白COOH-末端区域的存在是重要的融合的最后步骤。
The role of the simian virus 5 (SV5) fusion (F) protein 20 residue COOH-terminal region, thought to represent the cytoplasmic tail, in fusion activity was examined by constructing a series of COOH-terminal truncation mutants. When the altered F proteins were expressed in eukaryotic cells, by using the vaccinia virus-T7 transient expression system, all the F proteins exhibited similar intracellular transport properties and all were expressed abundantly on the cell surface. Quantitative and qualitative cell fusion assays indicated that all of the F protein COOH-terminal truncation mutants mediated lipid mixing with similar kinetics and efficiency as that of wild-type F protein. However, the cytoplasmic content mixing activity decreased in parallel with the extent of the deletion in the F protein COOH-terminal truncation mutants. These data indicate that it is possible to separate the presumptive early step in the fusion reaction, hemifusion, and the final stage of fusion, content mixing, and that the presence of the F protein COOH-terminal region is important for the final steps of fusion.